Vintage Cars: 1929 Hupp century 6 cy 4 dr sdn, quality machine shop, oversize pistons

Question
Engine compression done on all 6 cyl, read 72,78,72,75,75,75.  Any info re what the compression should be would be helpful.  Engine starts and runs now after 60 or 70 years idle.  Blows a massive amount of blue smoke.  Oiled thru spark plug holes before starting.  Any helpful info would be appreciated.

Answer
Russ, the compression is a bit low - you'd like to see numbers around 90. The bad news is that they're even, indicating you don't have a stuck valve or one cylinder that's causing a problem. It sounds like to me that your engine has got wear in the cylinder walls, possibly even some scoring due to the extensive time it spent idle. Oiling thru the spark plug holes helped, but there was probably a certain amount of corrosion on the cylinder walls from 60 years without lubrication.

The good news is that Hupp blocks are REALLY robust, and there's a fair amount of material in the cylinders that you can overbore, so you shouldn't have any difficulty rebuilding the engine. Egge Machine (or any quality machine shop) can supply oversize pistons and rings to fit your car, so if you do decide to rebuild, you can be sure that your car will run well once the job is done, and will last a good long time because the Chrome-Nickel alloy that Hupp used in their engine blocks is really tough.

Good luck - hope this helps!

Regards

Dick.